Hydraulic transmission



Aug. 10, 1943. I R. M. scHAl-:FER ET AL. 2,326,570 Y HYDRAULIC TRANSMISS ION n Aug 10, 1943- R. M. SCHAEFER ET AL 2,326,570

HYDRAULIC TRANSMISSION Filed Aug. 6, 1941 2 Sheets-Sheet 2 specially designed for use with Yinrit-mm1 Aug. 1o, im

RobertM. SchaeferandWilburEShm-tsacine, Wis., assignors to Twin Disc Clutch Company, Racine, Ws., a. .corporation of application August s, 1941,' sei-isi No. 405,690 i (ci. zi-i895) S Glains. Our invention relates to hydraulic transmissions and more particularly to one that is super-charging blowers for internal combustion engines.

Considerable difficulty has been encountered heretofore with straight gear ons between the engine and `supercharger because of their rigid and inelastic nature, Vthe involved shafting being twisted to such an extent during sudden increases or decreases in the engine speed that it is frequently sheared.

We have ascertained that a. hydraulic coupling will serveas an ecient and elastic connection under the foregoing circumstances provided that some means are employed to lay-pass the drive around the coupling at speeds considerably lower than the most eective transmitting speed of the coupling. such as when the engine is being cranked. Under these conditions, therspeed of the engine is only a fraction of its normal speed so that if a 'hydraulic coupling provided the con` nection to'the supercharger, the slip in the coupling `would be so great that the supercharger would be rendered ineffective for its primary 1111113059- Y It is therefore the principal object of our invention to devise a supercharger driv'mg mecha- .i smssroN Fig. is a sectional elevation showing a. modied form of our which utilizes a plan system of gearing. r

Referring to Fig. 1, the numeral I0 designates an internal combustion engine'which may be of the gasoline or Diesel type and which is provided with the cam shaft Il having attached thereto a. pinion l2. This pinion, as hereinafter described, is drivably connected to the supercharger i3 by means of a system of gearingv indicated by the numeral I4 and a hydraulic coupling i5, the g and coupling combination more particularly constituting our invention. For purpose of illustration, the supercharger i3 is indicated as being of the Roots blower or positive displacement type and the transmission referred to is connected to-one of the rotors of the 111-1 Air delivered by the super- Diesel engine, while for gasoline engines air may be delivered to the engine cylinders in nism which embodies ahydraulic coupling through which the drive is effected over one predetermined range of speed of the engine and a gear train which transmits the drive directly to the supercharger over a lower gine speed. Y

A further object is to devise a on of the character indicated wherein the drive through the gear .train is automatically thrown into or out ofY operation at a predetermined engine speed. Y

These and further objecis of our invention will be set forth in the following specification, referen being had to the accompanying drawings, and the novel means by which said obiec areeil'ectuatedwillbe deilnitelypointedoutin the claims.

In the drawings:

Eig. 1 is an elevation range of erii5 ofaSlrperclmi-gerY equipped. internal showing our improved hydraulic transmision applied thereto.

Eg.2isanen1arged.secionalelevationofthe transmimionasviewedinligl.

li'ig.3isannlarged,sectipnalongtheline 33inHg.2showlngafreewheelhigorover running clutch connection that forms animportant partoi' our invention.

any of the ways now commonly employed in the art. Our invenon is not restricted to the type of super i 'u f stated, but may be just as easily applied to a centrifugal blower. Moreover,-our 'n ,l slows. may be driven directly by the engine crank shaft instead of the cam shaft.

The form of our invention which is shown more or less 1. n n tically in Fig. 1 is more particularly illustrated in Figs. 2 and 3 to which reference will now be made. The cam shaft'pinion l2 meshes with a gear ll that is keyed to a coun il, whose opposite ends are jourmw :a a:

Alsototheshaftlisapinion that meshes with a gear 22 secured to ashaft 23 and keyedto is an impeller 24 having the usual radial blades 25. Theimpeller islocated in ve relation to a ruimer 26 having 2l' that are similar to the blades 25. The

impeller and runner together constitute the hypanes into an intake pipe I6, in the case la l! and 20 that may be support-A ed by any convenient portion of the engine bloc.

generally indicative 'on circuit. Sincev rotors (not shown). The pinion 36 is drlvably connected through a gear (not shown) to the other rotor. Since the internal construction of this supercharger is well known it has not been illustrated in the drawings.

The runner 26 surrounds the impeller 24 and so constitutes a housing for the coupling and secured to the runner adjacent the gear 22 is a gear 33 which is coaxial with the shaft 23 that is journaled freely thereon or in spaced relation thereto. The gear 33 meshes with a pinion 34 which surrounds a clutch sleeve 35 that is secured to the shaft I8.` interposed between the adjacent surfaces of the pinion 34 and sleeve 35 is a plurality of rollers 36 which are circumferentially spaced around the sleeve 35 and which operate in channels or slots 31 dened by the mentioned surfaces. Movement of these rollers in a clockwise direction relative to the sleeve 35,

as viewed in 3, is prevented by means of shoulders 38 formed on the sleeve. When this sleeve is rotated in a clockwise direction, as viewed in Fig. 3, the rollers 36 are moved outwardly along the surfaces 39 to establish a clutching connection `with the internal surface of the pinion 34. The arrangement thus described, therefore, constitutes a free wheeling or overrunning clutch connection between the pinion 34 and sleeve 35 for a purpose presently discussed. This clutch is only diagrammatically illustrated in the drawings and it will be understood that any of the usual spring arrangements may be employed to insure positive engagement of all the rollers.

vIn describing the operation of our improved transmission, it will be assumed that the cam shaft Il rotates counterclockwise when viewed in the direction of the arrow in Fig. 1. When the engine is .operating over its normal working range, the drive of the supercharger I3 is ac complished through the gear I1, pinion 2|, gear 22, shaft 23 and the hydraulic coupling 25 to the pinion 30:` Under these circumstances,` the clutch rollers 36 will occuy the positions generally shown in Fig. 3, or in other words, the pinion 34 overrides the rollers 36, so that direct gear drive to the runner 26 is interrupted.

However, at relatively lower speeds, than those indicated, such as when the engine is being cranked, the slip in the coupling is so great that it is necessary toY provide a direct gear driving connection vto the supercharger in order to insure an adequate output of air. Under these conditions, the rotation of the sleeve 35 relative to the pinion 34, i. e., in a clockwise direction, as viewed in Fig. 3, causes the rollers 36 to move outwardly lalong the'surface 39 to establish a clutching engagement with the pinion 34 and hence a direct gear connection to the runner 26 and thence to the pinion 30.

The change from coupling to gear drive and vice versa is accomplished automatically in response to changes in speed of the power source. The free wheeling connection can be designed to provide for any per cent of slip in the coupling before the free wheeling connection again engages. This feature is a matter of design that will vary with operating conditions and hence it is unnecessary to establish any definite limits in this respect. In one particular instance, the free wheeling connection was designed to accommodate a 15 per cent slip.

In Fig. 4 is illustrated a modified arrangement of our improved transmission which embodies a.

- thereto `sis an impeller 42.

planetary system of gearing. In this modication, the cam shaft pinion I2 meshes with a gear 40 which is keyed to a shaft 4I and secured An internal gear 43 `is secured to one side of the impeller and meshing with this gear is one or more planet pinions 44, each of which is rotatably mounted upon a stub shaft 45 that is secured to an annular cover 46 forming a part of a hydraulic coupling 41. The cover 46 is attached to a runner 48 which is located in cooperative relation to the impeller 42 and is coaxially bored to receive a bearing 49 in which is journaled one end of the shaft 4l while the opposite end is journaled in a bearing 50 that may be carried by any convenient portion of the engine. A pinion 5l is secured to the runner 48 and is also keyed to a shaft 52 that is axially aligned with the shaft 4I and is connected to one of the supercharger rotors (not shown). The pinion 5I corresponds to the pinion 30 in Figs. 1 and 2 and it will be understood that the former is drivably connected ,to the other rotor of the supercharger.

Freely. journaled on the shaft 4I is a brake sleeve 53 formed at one end as a sun gear which meshes with the pinions 44 and at the opposite end is encircled by a ring 54 fast on a part 55 which may be a bracket or other support secured to the engine block. Disposed between the periphery of the last noted portion of the sleeve 53 and the. inner surface of the ring 54 is a plurality of brake rollers 56, it being understood that the sleeve 53, ring 54 and roller 56 constitute a oneway brake that may be arranged in a manner similar to that illustrated in Fig. 3 with the sleeve 53 corresponding to the sleeve 35.

When the engine is operating over its normal working range, the supercharger is driven through the coupling 41, since the drive under these conditions is transmitted by the gear 40, shaft and coupling 41 to the pinion 5I. At this time, the rollers 56 occupy positions corresponding to those indicated in Fig. 3 and the pinions 44 rotate freely on their shafts 45 and move around the teeth on the sleeve 53. However, at cranking speeds or at relatively lower speeds than those indicated in the normal working range, the rotation of the impeller 42 causes the pinions 44 to move the brake sleeve 5 3 to a station-ary position and thereafter the pinions 44 roll around the teeth on the sleeve 53 and establish a positive gear drive to the cover 46 and thence to the pinion 5|.

It will be understood that the hydraulic coupling portion of our transmission may include anyV number of working circuits and also that our transmission is not restricted to the particular type of coupling illustrated since the latter is intended to generally denote any type of uid turbine transmission circuit. Moreover, our invention is not; restricted to use with a superchargr since the latter is to be generically regarded as any load, while the engine l0 constitutes any source of power.

We claim:

1. A hydraulic transmission for connecting a i source of power and a load comprising a shaft,

an impeller secured to the shaft, an internal gear mesh with the pinions, and a one-way brake connection between the last named gear and a fixed part of the transmission wherebyv the drive is automatically shifted from the gear to the hydraulic portion at a predetermined speed of the source.

2. A power transmission for connecting driving and driven shafts comprising a hydraulic coupling having an impeller secured to the driving shaft and a vrunner secured to the driven shaft, planetary gear means between the impeller and runner and having planet pinions carried by the runner, and means coupled to the pinions including a one-way brake for providing a mechanical drive between the impeller and runner.

3. A power transmission for connecting driving and driven shafts comprising a hydraulic coupling having an impeller secured to the driving shaft and a runner secured to the driven shaft, planetary gear means providing a mechanical drive between the impeller and runner and having planet pinions carried by the runner,

a sun gear freely mounted on the driving shaft in mesh with the pinions, and a one-way brake coupled to the sun gear.

4. A power transmission for connecting driving and driven shafts comprising a hydraulic coupling having an impeller secured to the driving shaft and a runner secured to .the driven shaft, a shell secured to the runner in enclosing relation to the mpeller, planetary gear means providing a mechanical drive between the impeller and runner and having planet pinions carried by the shell, a sun gear freely mounted on the driving shaft in mesh with the pinionstand a one-way brake coupled to the sun gear.

5. A power transmission for connecting driving and driven shafts comprising a hydraulic cou' pling having an impeller secured to the driving shaft and a rimner secured to the driven shaft, a gear annulus secured to the impeller, a shell the driven shaft, planetary gear means between the members and having planet pinions carried by one of the members, and means coupled to the pinions including a one-way brake for providing a mechanical drive betweenvthe members.

7. A power transmission for connecting driving and driven shafts comprising a hydraulic coupling having an impeller member secured to the driving shaft and a runner member secured to the driven shaft, planetary gear means between the members having planet pinions carried by one of the members, a sun gear freely mounted on the driving shaft in mesh with the pinions, and a one-way brake coupled to the sun gear,

8. A hydraulic transmission for connecting a source of power and a load comprising a shaft, an impeller element secured to the shaft, an internal gear mounted on the impeller concentric with the shaft, a runner element, the impeller `and running elements constituting the hydraulic portion of the transmission, pinions meshing with the gear and rotatably connected to the rlmner I element, a gear freely journaled on the shaft in mesh with the pinions, and a one-way lbrake connection between thelasthamedgear and a xed part of the transmission whereby the drive is automatically shifted from the gear to the hydraulic portion at a predetermined speed of the source.

ROBERT M. SCHAEFER.

WILBUR F. SHURTS. 

